BB Top End & Cam, Air Gap Fits!
04-21-2014, 09:43 PM
#1
Racer
Thread Starter
BB Top End & Cam, Air Gap Fits!
ok, i can cross this off my bucket list.
i started with a 30 over 402 w TRW small dome pistons (L2383), 6272292 heads, crane hyd FT cam(don't remember the part number, but it was recommended for 9.5/1 or better compression up to 5500rpm), Performer 2.0, Holley 670 SA. i figure the CR was about 8-1
the leak down and compression checks before dis assembly showed no problems, although their were concerns here
http://forums.corvetteforum.com/c3-t...-bb-today.html
that my bores were distorted from a previous bore/hone without torque plates. as i suspected, that was not the case, my poor photography skills caused the appearance of the distorted bore. i had this confirmed and the bores measured locally.
i then measured the depth of the pistons in the bore, and the average was .012. so i selected a felpro .039 head gasket, and had CStraub send me the whole setup; he recommended the same roller cam used on other 402 builds, morel street lifters, push rods, crane gold rockers, push rods etc.
the fresh craigslist 702 heads i found cc'd at 98, netting me about 9.7-1
i also added an Air Gap, and Holley 750 Street HP with no choke, knowing my hood clearance would be very limited in the 73 vette w the stock hood. it fit, barely. not ideal, but CS told me to get the Air Gap in there at any cost, since in the next year or 2 ill be installing an L88 hood and painting the car.
anyways the results with no carb changes and a basic 16 deg initial +18 Mech advance were staggering in comparison to how the car ran before. i have only spun it to 6k, and she feels like she is ready to keep going. before she was flat as a dog till 3k, then died at 5k due to i believe weak or incorrect valve springs
just wanted to thank everyone here, show some pix and a vid, and add a special thank you to Chris for all the help.
Chris i know i had some issues during all this, and i thank you again for helping out a total newbie
Lear
i started with a 30 over 402 w TRW small dome pistons (L2383), 6272292 heads, crane hyd FT cam(don't remember the part number, but it was recommended for 9.5/1 or better compression up to 5500rpm), Performer 2.0, Holley 670 SA. i figure the CR was about 8-1
the leak down and compression checks before dis assembly showed no problems, although their were concerns here
http://forums.corvetteforum.com/c3-t...-bb-today.html
that my bores were distorted from a previous bore/hone without torque plates. as i suspected, that was not the case, my poor photography skills caused the appearance of the distorted bore. i had this confirmed and the bores measured locally.
i then measured the depth of the pistons in the bore, and the average was .012. so i selected a felpro .039 head gasket, and had CStraub send me the whole setup; he recommended the same roller cam used on other 402 builds, morel street lifters, push rods, crane gold rockers, push rods etc.
the fresh craigslist 702 heads i found cc'd at 98, netting me about 9.7-1
i also added an Air Gap, and Holley 750 Street HP with no choke, knowing my hood clearance would be very limited in the 73 vette w the stock hood. it fit, barely. not ideal, but CS told me to get the Air Gap in there at any cost, since in the next year or 2 ill be installing an L88 hood and painting the car.
anyways the results with no carb changes and a basic 16 deg initial +18 Mech advance were staggering in comparison to how the car ran before. i have only spun it to 6k, and she feels like she is ready to keep going. before she was flat as a dog till 3k, then died at 5k due to i believe weak or incorrect valve springs
just wanted to thank everyone here, show some pix and a vid, and add a special thank you to Chris for all the help.
Chris i know i had some issues during all this, and i thank you again for helping out a total newbie
Lear
04-22-2014, 11:05 AM
#3
Le Mans Master
Good info, thanks for the post!
Lots of people always ask if they can stuff an RPM air gap under a 73 hood.
We just got our roller cam kit from CStraub as well for a 408" BBC we are building right now. We are hoping it makes some jam.
Lots of people always ask if they can stuff an RPM air gap under a 73 hood.
We just got our roller cam kit from CStraub as well for a 408" BBC we are building right now. We are hoping it makes some jam.
04-22-2014, 05:19 PM
#4
Racer
Thread Starter
thx guys...im sure the 408 will rock...fwiw the vented lids about 3/8" above the top of the carb, i know its a far from ideal situation...but the air gap is in there....
04-23-2014, 08:53 AM
#5
Burning Brakes
Excellent! Excellent! Excellent!
Im so glad you did this, and I hope people refer to this post in the future. I remember asking you questions in the past about your Performer 2-0 that you had before, and was thrilled that someone pulled that off successfully.
Because of your earlier posts, I bought a Perfomer 2-0, that still needs some work prior to installation. You took it a step further and proved that you can fit a pretty tall manifold under the 73-79 hoods with a BBC.
Car looks and sounds great. Thanks for sharing and best of luck!
Im so glad you did this, and I hope people refer to this post in the future. I remember asking you questions in the past about your Performer 2-0 that you had before, and was thrilled that someone pulled that off successfully.
Because of your earlier posts, I bought a Perfomer 2-0, that still needs some work prior to installation. You took it a step further and proved that you can fit a pretty tall manifold under the 73-79 hoods with a BBC.
Car looks and sounds great. Thanks for sharing and best of luck!
04-24-2014, 09:36 AM
#6
Racer
Thread Starter
thx dave, i remember the 2.0 stuff also...ive also had a couple pms asking for specifics on the air gap fit. when i get home this weekend ill take some pix and start a new post